The invention is directed to braces or orthotic devices used in the treatment of spinal disorders and, more particularly, to hyperextension back braces used in the treatment of spinal disorders.
Hyperextension back braces are used to reposition the spine in a hyperextended position to alleviate the pain often associated with various types of spinal disorders. These braces may also serve to correct or prevent deformation of the spinal column, such as may result from the multiple compression fractures frequently experienced by women suffering from osteoporosis.
Conventional hyperextension back braces, such as disclosed in U.S. Pat. No. 4,173,973 to Hendricks, typically apply pressure at the pelvis and sternum of a patient. This pressure applied at the front of the thoracic region of the patient is then counterbalanced by pressure applied with straps and a posterior pad positioned at the desired location along the spine. By applying pressure in this three-point arrangement, the spinal column can be moved from a hyperflexed or slumped posture to a hyperextended position. When the spinal column is placed in the hyperextended position, the joint space between adjacent vertebra is increased, thereby relieving compressive pressure and associated pain along the spinal column.
A significant problem associated with conventional hyperextension back braces is the inability of these devices to sufficiently protect against vertical movement of the spinal column. During normal daily activities, an individual is likely to bend or otherwise move in a manner which causes further compressive loading along the length of the spinal column. This compressive loading can cause pinching of nerves between inter-vertebral discs with resulting momentary or prolonged pain. Conventional hyperextension back braces are designed to maintain the spine in a hyperextended position but are not well suited to reduce these compressive loading forces.
It has also long been recognized that certain types of lower back pain in humans can be treated by wearing corset type devices. These devices are applied around the torso of the individual and are tightened to cause an increase in the intra-abdominal pressure in the wearer. The increased intra-abdominal pressure in turn functions to reduce the compression force on the individual's spine by creating a semi-rigid hydra-pneumatic cylinder surrounding the spinal column. The load normally carried by the spine is distributed across this cylinder and the pressure on the lumbar inter-vertebral discs is correspondingly reduced. In many cases, the reduction in pressure also serves to provide dramatic relief in the pain associated with the spinal disorder.